The aim of the paper is to show the effects of modelling the soil reaction coefficient on the base grid structure and their foundation. That kind of the structure is commonly used for the objects built on the far away locations because of the little environmental ground impact. Basically, the shallow foundation system is supporting grid construction used as a base for building the object above. The grid construction itself can occur in two extreme forms known as rigid and soft grids. The test example process both forms and monitors their structural response as well as the contact with the underlying structure. For the purpose of the soil reaction coefficient modelling the Se_Calc programmatically solution was developed.